A mulch layer should be maintained at about 2-4 inches in depth. There are several concerns you should have if you apply the mulch before the frost is gone:
1. This will delay emergence of plants.
2. The new mulch layer will temporarily tie up the nitrogen for the growing plants.
3. It is important not to cover the crowns of the plants in the ground. If we have a wet spring the moisture could cause stem rot.
4. Over mulching can choke our shallow-rooted plants and promote canker growth on susceptible trees and shrubs.
Wait until the early growing plant material appears. Such as; tulips, daffodils, hosta; etc., then apply a light mulch layer near the plant itself and gradually thicken the mulch as you move away from the plant.
